JP2007309304A - Internal combustion engine for motorcycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an internal combustion engine for a motorcycle mounted on a vehicle in such a manner that a plurality of cylinders are protruded on right and left both sides of a vehicle width direction, capable of preventing oil rise at resting of a cylinder, and capable of reducing oil consumption. <P>SOLUTION: In the internal combustion engine E for the motorcycle mounted on the motorcycle having a side stand 7 supporting the vehicle body in a tilt state on one of the right and left sides in such a manner that the plurality of the cylinders are protruded on both right and left sides of the vehicle width direction, a cylinder resting mechanism 50 for resting combustion is provided on the cylinder on the opposite side from the side stand 7 of the cylinders protruded on the right and left both sides. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an internal combustion engine mounted on a motorcycle that supports a vehicle body by tilting a side stand, and more particularly to an internal combustion engine having at least two cylinders equipped with a cylinder deactivation mechanism.

  There is an example in which a multi-cylinder internal combustion engine that improves the fuel consumption by stopping the operation of some of the plurality of cylinders according to the operating state is mounted on a motorcycle (see, for example, Patent Document 1). .

JP 2005-90463 A

The internal combustion engine disclosed in the embodiment of the specification of Patent Document 1 is an in-line four-cylinder internal combustion engine that is mounted on a motorcycle with a crankshaft oriented in the vehicle body width direction.
Two intake valves and two exhaust valves that are slidably supported by the cylinder head are provided for each cylinder. A valve suspension mechanism (hydraulic lifter built-in type valve) that is operated by oil pressure in the lifters of these intake and exhaust valves. (Pause mechanism) is provided.
The cylinder can be deactivated by suspending all the intake / exhaust valves of one cylinder by the valve deactivation mechanism and closing all the port openings of the combustion chamber.

In the normal working cylinder in the normal operating state, the negative pressure is mainly generated only in the intake stroke in the four strokes of one cycle, but in the idle cylinder, combustion in the explosion stroke does not occur. The negative pressure is generated in the cylinder in the two strokes of the explosion stroke and the intake stroke in the four strokes of the cycle, and the period in which the negative pressure in the cylinder is generated is twice as large as that of the regular cylinder. End up.
Along with this, a phenomenon in which the oil in the crank chamber is sucked into the combustion chamber, so-called oil rise, is likely to occur. However, as in the case of the in-line four-cylinder internal combustion engine described in Patent Document 1, usually the vehicle body is greatly inclined. Since the cylinder head (combustion chamber) is always located above the crankcase (crank chamber), the oil accumulated in the lower part of the crank chamber is difficult to move into the combustion chamber, so that the oil rise is suppressed.

However, in the case of an internal combustion engine mounted on a vehicle with a plurality of cylinders protruding left and right in the vehicle width direction, the cylinder head may be located below the crankcase due to the inclination of the vehicle body.
In particular, when the cylinder head is below the crankcase in the side stand side cylinder when the vehicle body is tilted and supported by the side stand when the vehicle is stopped, the oil in the crank chamber is in a state of moving toward the cylinder, If the cylinder is a deactivated cylinder, oil increase cannot be suppressed when the cylinder is deactivated, and a large amount of oil is sucked into the combustion chamber, increasing oil consumption.

  The present invention has been made in view of the above points, and an object of the present invention is an internal combustion engine mounted on a vehicle with a plurality of cylinders projecting from the left and right sides in the vehicle width direction. Is to provide an internal combustion engine for a motorcycle that can prevent oil consumption and reduce oil consumption.

  In order to achieve the above object, according to the first aspect of the present invention, there is provided a motorcycle having a side stand that supports the vehicle body in an inclined state on one of the left and right sides of the vehicle body, and a plurality of cylinders projecting to the left and right sides in the vehicle width direction In the internal combustion engine for a motorcycle mounted in such a manner, the internal combustion engine for a motorcycle provided with a cylinder deactivation mechanism for suspending combustion in a cylinder on the opposite side to the side stand among the cylinders protruding on the left and right sides.

  According to a second aspect of the present invention, in the internal combustion engine for a motorcycle according to the first aspect, the cylinder deactivation mechanism includes a hydraulic lifter built-in valve deactivation mechanism in a cylinder head.

  According to a third aspect of the present invention, in the internal combustion engine for a motorcycle according to the second aspect, a hydraulic control valve for controlling the hydraulic pressure of the valve lift mechanism with a built-in hydraulic lifter is disposed above the idle cylinder. And

  According to a fourth aspect of the invention, in the internal combustion engine for a motorcycle according to the first aspect, the internal combustion engine has three regular cylinders projecting on the same side as the side stand, and three idle cylinders on the opposite side of the side stand. There are a total of 6 cylinders protruding, and the explosion timings of the 6 cylinders are set at equal intervals, and the explosion timings of the 3 regular cylinders are also set at equal intervals.

  According to the internal combustion engine for a motorcycle according to claim 1, since the cylinder deactivation mechanism for suspending combustion is provided in the cylinder on the side opposite to the side stand, when the vehicle is stopped with the vehicle body tilted by the side stand. The idle cylinder is on the opposite side of the side stand and the cylinder head is positioned above the crankcase, that is, the combustion chamber is above the crank chamber, so that oil rise during cylinder idle is suppressed and oil consumption Can be reduced.

  According to the internal combustion engine for a motorcycle according to claim 2, since the cylinder deactivation mechanism is constituted by a valve deactivation mechanism with a built-in hydraulic lifter in the cylinder head, among the cylinders projecting to the left and right sides, the deactivation cylinder side is the regular cylinder. However, since the side stand is provided on the regular cylinder side, the weight balance in the left-right direction of the vehicle is good.

  According to the internal combustion engine for a motorcycle according to claim 3, since the hydraulic control valve for controlling the hydraulic pressure of the hydraulic lifter built-in valve pausing mechanism is disposed at the upper part of the pausing cylinder, the pausing that projects to the left or right side is provided. The cylinder serves as a barrier to protect the hydraulic control valve from flying stones, and does not require a special protective cover and has good appearance.

  According to the internal combustion engine for a motorcycle according to claim 4, the internal combustion engine is composed of a total of six cylinders in which three regular cylinders protrude on the same side as the side stand and three idle cylinders protrude on the opposite side of the side stand, The explosion timing of the 6 cylinders is set at regular intervals, and the explosion timing of the 3 regular cylinders is also set at regular intervals, so the regular 3 cylinders explode at regular intervals during idling, reducing vibration and rotation fluctuations. can do.

Hereinafter, an embodiment according to the present invention will be described with reference to FIGS.
FIG. 1 is an overall right side view of a motorcycle 1 on which an internal combustion engine E for a motorcycle according to the present embodiment is mounted. FIG. 2 is a view of the motorcycle 1 in a state of being supported by a side stand 7 and stopped. FIG.
In the present specification, the vehicle forward direction is defined as the forward direction, the opposite direction is defined as the rear direction, and the left hand direction is determined as the left direction and the right hand direction is determined as the right direction as viewed from the forward direction.

  In the motorcycle 1, an internal combustion engine E is suspended from a vehicle body frame 2 extending rearward from a head pipe, and a front wheel FW is mounted on a lower end of a front fork 3 that extends obliquely forward and downward from a steering shaft that is pivotally supported by the head pipe. Is supported, and the steering wheel 4 is configured with the upper portion of the steering shaft extending left and right.

A rear wheel RW is pivotally supported at the rear end of the rear fork at the rear of the vehicle body, and a seat 5 on which a driver and a passenger are seated is disposed above and obliquely in front of the rear wheel RW.
A main stand 6 is provided at the lower end of the vehicle body frame 2 in front of the rear wheel RW, and a side stand 7 is provided at a position along the rear part of the internal combustion engine E on the left side of the vehicle body frame 2 in front of the main stand 6.

The front part of the vehicle body is covered with a front cover 8, and storage cases 9 are provided on both sides and the upper part of the rear wheel RW at the rear part of the vehicle body.
The internal combustion engine E according to the present embodiment mounted on such a motorcycle 1 is a six-cylinder horizontally opposed internal combustion engine of a four-stroke cycle, and is projected horizontally by three cylinders on both the left and right sides in the vehicle width direction. Yes.

The three cylinders projecting to the left of the vehicle body are integrally arranged in series in the front-rear direction to form the left engine block _BL, and the three cylinders projecting to the right side of the vehicle body are integrally arranged in series in the front-rear direction to form the right engine block _BR is constituted.

As shown in FIG. 2, to be in a state where the motorcycle 1 is stopped is supported by the side stand 7, the horizontal opposed type internal combustion engine E, the left engine block B _L downward, tilting the right engine block B _R upward Kept in a good posture.

  Referring to FIGS. 3 and 4, the internal combustion engine E is rotatably supported so that the left and right crankcases 11L and 11R have a crank chamber 11c inside and sandwich the crankshaft 10 from the left and right. ing.

The left and right cylinder blocks 12L and 12R are superimposed on the left and right outer sides of the left and right crankcases 11L and 11R, respectively, and the left and right cylinder heads 13L and 13R are superimposed on the outer sides of the left and right cylinder blocks 12L and 12R. 13L, the outer cylinder head cover 14L of 13R, 14R constitute the left and right engine blocks _B L, _{B R} covers.

Pistons 15L and 15R are slidably fitted in three cylinder bores arranged in series on the left and right cylinder blocks 12L and 12R, respectively, and between the piston pins of the pistons 15L and 15R and the crank pins of the common crankshaft 10. The left and right connecting rods 16L and 16R are connected.
The cylinder bore of the left cylinder block 12L is offset backward with respect to the cylinder bore of the right cylinder block 12R.

Combustion chambers 20L and 20R are formed between the top surfaces of the sliding pistons 15L and 15R in the cylinder bore and the ceiling surfaces of the cylinder heads 13L and 13R facing the same.
One intake port 21L, 21R and one exhaust port 22L, 22R are opened on the ceiling surface of each combustion chamber 20L, 20R of the cylinder head 13L, 13R.

  The intake ports 21L and 21R and the exhaust ports 22L and 22R of the left and right cylinder heads 13L and 13R have the same substantially symmetrical structure, and are sectional views of one right cylinder head 13R (cut along line VV in FIG. 4). FIG. 5 shows a sectional view of the internal combustion engine.

Three combustion chambers 20R are arranged in the front and rear, a plug mounting hole 23R for attaching a spark plug is formed at the center of each combustion chamber 20R, and an intake port 21R is obliquely rearward above the plug mounting hole 23R of the combustion chamber 20R. An exhaust port 22R is opened obliquely forward.
The intake port 21R extends upward from the opening of the combustion chamber 20R, and the exhaust port 22R extends downward from the opening of the combustion chamber 20R.

  An intake valve 25R that opens and closes the opening of the intake port 21R in the combustion chamber 20R and an exhaust valve 26R that opens and closes the opening of the exhaust port 22R are alternately arranged in a line in the front-rear direction. The intake valve 25R and the exhaust valve The cam lobes of the common camshaft 30R come into contact with and drive the valve lifters 27R and 28R of 26R.

  Similarly, in the left cylinder head 13L, the intake port 21L extends upward from the combustion chamber 20L, the exhaust port 22L extends downward, and the intake valve 21L opens and closes the opening of the intake port 21L in the combustion chamber 20L. An exhaust valve 26L opens and closes the opening of the exhaust port 22L, and the cam lobes of a common cam shaft 30L come into contact with and drive the valve lifters 27L and 28L of the intake valve 25L and the exhaust valve 26L.

  Driven sprockets 31L, 31R are fitted to the front end portions of the left and right camshafts 30L, 30R, which are located on the left and right sides of the internal combustion engine E and are directed in the front-rear direction. Cam chains 33L and 33R are bridged between the attached drive sprockets 32L and 32R, so that the camshafts 30L and 30R rotate at a half rotation speed of the crankshaft 10.

  Chain chambers 34L and 34R for accommodating cam chains 33L and 33R are formed in front portions of the left and right crankcases 11L and 11R, cylinder blocks 12L and 12R, and cylinder heads 13L and 13R.

  The intake ports 21L and 21R extending upward from the combustion chambers 20L and 20R of the left and right cylinder heads 13L and 13R are connected to intake manifolds 35L and 35R, and the left and right intake manifolds 35L and 35R are close to each other on the upstream side. The throttle bodies 36L and 36R interposed between the two are adjacent to each other at the left and right centers (see FIGS. 2 and 4).

As shown in FIG. 4, fuel injection valves 38L and 38R protrude from bent portions near the connection portions of the intake manifolds 35L and 35R with the intake ports 21L and 21R.
Each throttle valve in the throttle bodies 36L and 36R is driven by a separate motor, and the state of drive control is shown in FIG.

FIG. 7 shows a relationship in which the throttle valve opening (throttle opening) is set with respect to the accelerator grip opening.
The opening of the throttle valve of the left throttle body 36L (throttle opening of the regular cylinder group) is as follows. The grip opening increases proportionally from 0% opening and is fully opened around 80% opening. Acting accordingly.

On the other hand, the opening of the throttle valve of the right throttle body 36R (throttle opening of the deactivated cylinder group) is fully closed when the grip opening is low, and starts to open around about 30% opening, It rises proportionally.
Therefore, in the idling state, the deactivated cylinder group is in the deactivated state, and when the deactivated state is released and the operation state is entered, the deactivated cylinder group starts operating smoothly and suppresses torque fluctuation.

The internal combustion engine E of approximately above structure, 3 cylinders of the left engine block B _L is that the usually conventional cylinders, three cylinders of the right engine block B _R is hydraulic lifter built-in valve This is a deactivated cylinder provided with a cylinder deactivation mechanism composed of the deactivation mechanism 50.

The structure of this idle cylinder hydraulic lifter built-in valve pause mechanism 50 will be described with reference to FIG.
FIG. 6 shows that a pin holder 52 is slidable in the axial direction in a bottomed cylindrical valve lifter 28R which is provided at the upper end portion of the valve stem 26Ra of the exhaust valve 26R and reciprocally slides in contact with the cam lobe of the camshaft 30R. The pin holder 52 is fitted into the valve lifter 28R by a coil spring 59 and pressed against the bottom surface of the valve lifter 28R via a shim 58.

  The pin holder 52 has an insertion hole 52a through which the valve stem 26Ra is inserted and a sliding hole 52b orthogonal to the insertion hole 52a, and a slide pin 53 is slidably fitted into the sliding hole 52b. One end of the pin 53 is urged by a return spring 54, and a hydraulic chamber 55 is formed at the other end, and sliding is restricted by abutting against a stopper pin 56 provided in the hydraulic chamber 55.

The slide pin 53 is formed with an accommodation hole 53a that is coaxially connected to the insertion hole 52a of the pin holder 52 in a state in which the slide pin 53 is urged by the return spring 54 and regulated by contacting the stopper pin 56.
An oil passage 57 in the cylinder head 13R communicates with the hydraulic chamber 55 in the sliding hole 52b of the pin holder 52.

  Accordingly, when the hydraulic pressure acting on the slide pin 53 is low pressure, the hydraulic lifter built-in valve resting mechanism 50 causes the slide pin 53 to abut against the stopper pin 56 by the urging force of the return spring 54. The upper end portion of the valve stem 26Ra through which the insertion hole 52a of the pin holder 52 is inserted is in the accommodation hole 53a, so that the valve lifter 28R slides in the valve opening direction together with the pin holder 52 by the rotation of the camshaft 30R. Even so, the upper end portion of the valve stem 26Ra is accommodated in the accommodation hole 53a, and the exhaust valve 26R does not act on the exhaust valve 26R, so that the closed state is maintained.

  On the other hand, at the time of operation when the hydraulic pressure acting on the slide pin 53 is high, the slide pin 53 slides against the urging force of the return spring 54 by the pressure oil to close the opening of the insertion hole 52a of the pin holder 52. Therefore, when the upper end portion of the valve stem 26Ra through which the insertion hole 52a is inserted comes into contact with the slide pin 53, the valve lifter 28R is pressed together with the pin holder 52 by the rotation of the camshaft 30R and slides in the valve opening direction. A pressing force acts on the exhaust valve 26R through 53 to open the exhaust port 22R, and the exhaust valve 26R is opened and closed in accordance with the reciprocation of the valve lifter 28R.

  The above valve deactivation mechanism 50 is also incorporated in the valve lifter 27R of the intake valve 25R. When the cylinder is deactivated, both the intake valve 25R and the exhaust valve 26R are activated, and all the two valves 25R are operated. , 26R close the intake port 21R and the exhaust port 22R.

Such cylinder deactivation mechanism is provided in the 3-cylinder of the right engine block B _R, spool valve 60 for controlling the hydraulic pressure of the valve resting mechanism 50 on the top of the right engine block B _R are disposed.
As shown in FIG. 1 and FIG. 2, the spool valve 60 protrudes at a location that does not interfere with the intake manifold 35R at the upper portion of the right engine block _BR , which is approximately the center of the cylinder block 12R of the central cylinder and the cylinder head 13R. ing.

Therefore, the spool valve 60 can be protected from flying stones or the like right engine block B _R and the intake manifold 35R becomes a barrier, without the need for special protection cover or the like, and appearance is good.

3 cylinders of the left engine block B _L facing horizontally in the rest three cylinders of the right engine block B _R is typically conventional cylinders.
The explosion timings of all six cylinders of the internal combustion engine E are set at equal intervals, and the explosion timings of the three regular cylinders are also set at equal intervals.

  Therefore, not only when all 6 cylinders are running, but also when the idle 3 cylinders are idle and when the regular 3 cylinders are operating, such as when idling, the 3 cylinders explode at equal intervals, reducing vibration and rotational fluctuations. can do.

As shown in FIG. 2, when the motorcycle 1 is stopped with the vehicle body tilted to the left and supported by the side stand 7 provided on the left side, the cylinder head 13 </ b> _R Since the combustion chamber 20R is located above the crank chamber 11c, the oil rise during cylinder deactivation is suppressed and the oil consumption can be reduced.

If the idle cylinder is provided on the side stand side, the oil in the crank chamber 11c is moved toward the cylinder when the vehicle body is tilted and supported by the side stand, and the oil rises when the cylinder is deactivated. As a result, a large amount of oil is sucked into the combustion chamber.
In the internal combustion engine E according to the present embodiment, the left engine block _BL on the side stand 7 side is the regular cylinder, so the regular cylinder only generates a negative pressure in the combustion chamber only by the intake stroke, and oil rise is almost a problem. do not become.

Suspendable cylinder of the right engine block B _R of the side stand 7 and opposite side, so that the valve resting mechanism 50 is built valve lifter 27R, the 28R, among halted cylinder side of the cylinder projecting to the left and right sides (right engine block B _R) Although but the weight gain than regular cylinder side (left engine block B _L), since the side stand 7 is provided on the normal cylinder side, the weight balance between the left and right direction of the vehicle is improved.

1 is an overall right side view of a motorcycle equipped with an internal combustion engine for a motorcycle according to an embodiment of the present invention. FIG. 3 is a front view of the motorcycle in a state of being supported by a side stand and stopped. It is sectional drawing of the internal combustion engine cut | disconnected by the III-III line | wire of FIG. It is sectional drawing of the internal combustion engine cut | disconnected by the IV-IV line | wire of FIG. It is sectional drawing of the internal combustion engine cut | disconnected by the VV line | wire of FIG. It is sectional drawing which shows the structure of a hydraulic lifter built-in type valve stop mechanism. It is a figure which shows the set relationship of the throttle opening with respect to a grip opening.

Explanation of symbols

1 ... Motorcycle,
E ... Internal combustion engine, B _L ... Left engine block, _BR ... Right engine block, 7 ... Side stand, 10 ... Crankshaft, 12L ... Left cylinder block, 12R ... Right cylinder block, 13L ... Left cylinder head, 13R ... Right cylinder Head, 25L, 25R ... intake valve, 26L, 26R ... exhaust valve, 27L, 27R, 28L, 28R ... valve lifter, 50 ... valve rest mechanism, 52 ... pin holder, 53 ... slide pin, 60 ... spool valve.

Claims (4)

In an internal combustion engine for a motorcycle that is mounted on a motorcycle having a side stand that supports the vehicle body in an inclined state on the left and right sides of the vehicle body, with a plurality of cylinders projecting from the left and right sides in the vehicle width direction.
An internal combustion engine for a motorcycle, comprising a cylinder deactivation mechanism for deactivating combustion in a cylinder on the opposite side of the side stand among the cylinders projecting to the left and right sides.   The internal combustion engine for a motorcycle according to claim 1, wherein the cylinder deactivation mechanism is configured by a hydraulic lifter built-in valve deactivation mechanism in a cylinder head.   The internal combustion engine for a motorcycle according to claim 2, wherein a hydraulic control valve for controlling the hydraulic pressure of the hydraulic lifter built-in valve deactivation mechanism is disposed above the deactivation cylinder. The internal combustion engine is composed of a total of six cylinders in which three regular cylinders protrude on the same side as the side stand and three idle cylinders protrude on the opposite side of the side stand.
The explosion timing of 6 cylinders is set at equal intervals,
The internal combustion engine for a motorcycle according to claim 1, wherein the explosion timings of the three regular cylinders are also set at equal intervals.

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